Gmguy6872

Ok. So I posted a long time ago about rear light issue and finally fixed it. (Broken wire)

Now... I have another problem. I have no headlights or taillights or side markers. They were working fine then the next day nothing. I looked over the fuse panel didn't see any blown fuses. I have hazards, signals and brake lights. But not headlights or taillights.

I'm at my wit's end.... Please help.

oldcutlass

Do the dash lights work, brake lights, and courtesy lights work? On your headlight switch plug is a red wire, is there 12v on it?

Gmguy6872

yes. Everything but my dash lights. But they weren't working when the headlights were. But I do have hazards, brakes and signals in both the front and rear.

oldcutlass

Check that red wire for voltage and make sure the headlight switch plug is seated.

joe_padavano

The brake/turn/hazard lights are a completely separate circuit, completely different wires, and completely different bulb filaments from the rest of the lights. They are unrelated to the lights you are having trouble with.

A quick look at the wiring diagram in the CSM shows you that the only thing that the headlight circuit has in common with the taillights/parking lights/side markers is the sliding contact bar in the headlight switch, period. Even the power wires for the two circuits are different. The headlights themselves do not have a fuse - there is a self-resetting circuit breaker built into the headlight switch. This breaker DOES NOT feed the park/tail/side lights, only the headlights. The TAIL fuse feeds the other circuit.

Both the fuse panel and the headlights are fed by the heavy red wire from the horn relay stud, but that wire also feeds the ignition switch, so if it were bad the car would not start either. There is a splice in the harness under the dash where the red wire splits into three wires to feed the ignition switch, headlight circuit, and fuse panel. It is highly unlikely that this splice could fail in a way that only feeds one of the three wires.

Either the headlight switch is bad or you have multiple independent failures that coincidentally happened at the same time. The only other potential failure mode is that the plastic connector for the headlight switch has overheated and melted. This actually happened to me on a Chevy truck.

Pull the connector from the headlight switch and check for power on the red wire that feeds the headlight circuit and the black wire with white stripe that feeds the park/tail/side light circuit.

oldcutlass

They are all powered by the red wire that feeds both the 3 fuses and the headlight switch. That is the only common connection.

joe_padavano

As I noted above, if the ignition switch has power, that red wire is not the problem. The red wire also feeds the hazard flashers, which are working.